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AI system design interviewer
Requirements, capacity, data and trade-offs — practice driving a design conversation and get told exactly which part of your design was hand-waved.
Free 10-minute interview with a full report. Paid plans run full-length sessions.
System Design interview questions you might get
A sample of the starting questions. The live interview follows up on your answer, so no two sessions go the same way.
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Design a news feed for 50 million daily users. Push, pull or hybrid?
What it tests: Fan-out trade-offs.
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Design a rate limiter used by every API in the company.
What it tests: Distributed counters and accuracy.
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Design a chat system with read receipts and offline delivery.
What it tests: Real-time delivery and ordering.
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Your cache cluster just went down. What happens to your database, and how do you protect it?
What it tests: Failure-mode thinking.
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How would you design file upload for files up to 5 GB?
What it tests: Chunking, resumability and storage.
How a session works
About 20–30 minutes from setup to report. End any time and you still get feedback on what was covered.
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Set your target
Pick a role, level and stack. Add a job description or your resume if you want questions about your real projects.
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Answer live
Speak or type. The interviewer follows up on thin answers, raises the difficulty when you're doing well and switches to code when it fits.
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Read the notes
A report scores every competency, quotes the answers that cost you, and gives you a prep plan for the next session.
A report that quotes you, not a pat on the back
Every score links back to something you actually said.
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Competency scores
Weighted to the role you picked, so a system design gap counts more for a senior backend role than for a frontend junior.
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STAR check on every story
See which part of each behavioral answer was missing — usually the Result.
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How you sounded
Filler words, hedging, "I" versus "we", and whether you cited real numbers — measured from your words, and compared between the first and second half of the interview.
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A prep plan
The two or three things to practice next, and a skill graph that tracks them across sessions.
Competencies — sample report
STAR — "Tell me about a missed deadline"
How you sounded
Questions
Can I draw diagrams?
Sessions are conversational today; describe components and data flow in words. A whiteboard is on the roadmap.
What level is it for?
Mid to Staff. Choose Senior or Staff for deeper scaling and trade-off discussions.
How is a design scored?
Against weighted competencies: requirements, design, data, scaling and trade-offs, with evidence quoted from your answers.
Is it free to try?
Yes. Each month you get a free interview of up to 10 minutes with its scored report. Paid plans add full-length interviews, every track and the full 360 report.